1. Field
The present disclosure relates to the field of communications, and in particular to an information transmission apparatus, an information detection apparatus and a transmitter.
2. Description of the Related Art
Multiple sub-carrier signals are adopted in the multicarrier modulation technique, in which data streams are divided into several sub-data streams, so that the sub-data streams have much lower transmission bit rates, and these data are used to modulate several subcarriers, respectively. Multicarrier modulation signals are characterized in having relatively low transmission rates of subcarrier data and relatively long periods of code elements. Multicarrier modulation may be realized in multiple technical ways, such as discrete multi-tone (DMT), and orthogonal frequency division multiplexing (OFDM), etc.
A problem existed in the multicarrier modulation signals is that their peak to average power ratios (PAPRs) are relatively high. In practical applications, a peak value of an output signal of a transmitter is often limited; hence, in order to increase average power of the signals, the PAPRs of the signals need to be lowered. One of the most often used methods is to perform clipping directly on the multicarrier modulation signals. The multicarrier modulation signals are formed by superimposing multiple subcarrier signals, hence, in some special bitmaps, extremely high PAPRs will occur. Clipping operations on these symbols of extremely high PAPRs will produce very large signal distortion, thereby resulting in burst errors in these symbols. Although a probability of occurrence of such burst errors is not high and its effect on an average bit error rate is relatively few, the burst errors will result in a failure of forward error correction (FEC) decoding, thereby causing a communication failure.
Currently, a transmitter may process information transport blocks to be transmitted via multiple interleaving branches or multiple phase disturbing branches respectively, and then perform serial-to-parallel transform, mapping and inverse discrete Fourier transform (IDFT) respectively, and finally select a branch of a lowest PAPR to transmit the information transport blocks. In such a case, the transmitter needs to notify information on the selected branch (often referred to as side information) to a receiver, and the receiver performs corresponding processing after receiving the information. In the following, the “information on the selected branch” is referred to as “information indicating branch selection”. Following description is given taking an interleaving branch as an example. FIG. 1 is a flowchart of transmitting information transport blocks by an existing transmitter having multiple branches. As shown in FIG. 1, after an information transport block to be transmitted is interleaved by 1-M interleaving branches, performed serial-to-parallel transform and mapping respectively, and performed inverse discrete Fourier transform (IDFT), an interleaving branch of lowest PAPR is selected to transmit the information transport block, and furthermore, information on which interleaving branch is selected to transmit the information transport block is transmitted to a receiver. The information may be transmitted in multiple manners, such as directly selecting a subcarrier as a transmission path of the information, or directly interpolating a slot of the information into a time domain. A scheme of multiple phase disturbing branches is similar to what is described above, in which multiple interleaving branches are replaced with multiple phase disturbing branches, which shall not be described herein any further.
It should be noted that the above description of the background is merely provided for clear and complete explanation of the present disclosure and for easy understanding by those skilled in the art. And it should not be understood that the above technical solution is known to those skilled in the art as it is described in the background art of the present disclosure.